The Internet application is being widely found in various aspects of the society with a great influence on sociality and economy. The content on the Internet is being developed into voice, video and so on from text and picture. Meanwhile, with the constant improvement on the broadband access technology, a scale of the bandwidth of each subscriber is increased to Mbps from the original 64 kbps by means of digital subscriber line (Digital Subscriber Line, referred to as DSL) technology. The bandwidth of the subscriber may be improved to the Gbps scale by means of an optical access technology, such as fiber to the home (Fiber To The Home, referred to as FTTH) technology based on passive optical network (Passive Optical Network, referred to as PON). The network traffic rises rapidly under the dual-push of the network content and network access technology.
Internet Protocol (Internet Protocol, referred to as IP) is a basic service bearing protocol of the Internet, in which a router for implementing IP message forwarding is taken as a core device for forwarding the Internet service, whose capacity is increasingly great with the growth of the network traffic. However, due to the feature of packet-by-packet forwarding of the router, the router which satisfies the demand on capacity increases correspondingly both in power consumption and volume, and the router with a great capacity is difficult in design and high in cost. Meanwhile, since an operator charges the subscriber mainly from an access network currently, there is no motivation to invest in the expansion of a backbone network which becomes a bandwidth bottleneck with an influence on the Internet application and customer experience.
One of the methods for solving the problem of bandwidth bottleneck of the backbone network is to realize the traffic localization, that is, to reduce the network burden brought by the access of the subscriber to the content by storing the content to a place closer to the subscriber. Currently, the main method for realizing the traffic localization is to establish content delivery network (Content Delivery Network, referred to as CDN), that is, to dispose CDN node servers at different regions, these CDN node servers constituting a layer of intelligent virtual network on the basis of the existing Internet. In the existing CDN system, each CDN node server not only processes a subscriber request but also provides content supplied by a content provider to the subscriber. Since different content providers may support different application layer protocols, in order to satisfy the requests from the registered subscriber of different content providers, each CDN node server needs to update or upgrade the application layer protocol when there is a new content provider. Therefore, the demand on each CDN node server is relatively high, and the system management cost is relatively high.